Removing deprecated DCHECK's that require App Launcher to be user-level only.

With Chrome / App Launcher unification, the App Launcher can be installed at system-level. Old DCHECK's to enforce otherwise are creating bogus failures, and should be removed. 

This bug is triggered by https://chromiumcodereview.appspot.com/14711006/ , which adds "shadow" App Launcher Clients/ClientState keys to support 7DA tracking for App Launcher. Unfortunately, these keys are read, and are interpreted as the presence of App Launcher (thus triggering DCHECK).

A separate issue is that installation_validator complains about missing information in the "shadow" registry key. This is less urgent, and hence not part of this CL.

BUG=243432

Review URL: https://chromiumcodereview.appspot.com/15915003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202605 0039d316-1c4b-4281-b951-d872f2087c98

chrome/installer/setup/uninstall.cc

@@ -1140,8 +1140,6 @@ InstallStatus UninstallProduct(const InstallationState& original_state,
     DeleteShortcuts(installer_state, product, base::FilePath(chrome_exe));
 
   } else if (product.is_chrome_app_host()) {
-    // TODO(huangs): Remove this check once we have system-level App Host.
-    DCHECK(!installer_state.system_install());
     const base::FilePath app_host_exe(
         installer_state.target_path().Append(installer::kChromeAppHostExe));
     DeleteShortcuts(installer_state, product, app_host_exe);

chrome/installer/util/installation_validator.cc

@@ -115,8 +115,6 @@ BrowserDistribution::Type
 void InstallationValidator::ChromeAppHostRules::AddUninstallSwitchExpectations(
     const ProductContext& ctx,
     SwitchExpectations* expectations) const {
-  DCHECK(!ctx.system_install);
-
   // --app-launcher must be present.
   expectations->push_back(
       std::make_pair(std::string(switches::kChromeAppLauncher), true));
@@ -867,11 +865,6 @@ bool InstallationValidator::ValidateInstallationTypeForState(
     ValidateProduct(machine_state, system_level, *product_state,
                     chrome_app_host_rules, &rock_on);
     *type = static_cast<InstallationType>(*type | ProductBits::CHROME_APP_HOST);
-    if (system_level) {
-      LOG(ERROR) <<
-          "Chrome App Launcher must not be installed at system level.";
-      rock_on = false;
-    }
     if (!product_state->is_multi_install()) {
       LOG(ERROR) << "Chrome App Launcher must always be multi-install.";
       rock_on = false;